Python, blender and weird rotate behaviour after restoring matrix
In order to use the Matrix class you can either use import mathutils and mathutils.Matrix() to initialize an instance or from mathutils import Matrix and then Matrix().

import bpy
import mathutils


view_matrix = mathutils.Matrix(([0.9077774286270142, -0.4194521903991699, -6.8628960292471675e-09, 1.434309720993042],
                                [0.3097465932369232, 0.6703528165817261, 0.6743027567863464, 0.9151758551597595],
                                [-0.28283774852752686, -0.6121168732643127, 0.738455057144165, -0.902187168598175],
                                [0.0, 0.0, 0.0, 1.0])) 


for area in bpy.context.screen.areas:
    if area.type == 'VIEW_3D':
        for space in area.spaces:
            if space.type == 'VIEW_3D':
                v3d = space.region_3d   
                v3d.view_matrix = view_matrix
                v3d.view_perspective = 'ORTHO'
                break